Scope Chains and Closures in JavaScript

The goal of this talk is for you to understand scopes, scope chains, and closures. You will also be able to easily and quickly explain them to other developers.

There is a trend in developers resorting to a kind of hand-waving in their descriptions of these terms, “If you’ve ever had the situation where someone asked you about how scope chains or closures work, and you started the explanation […], but then all of a sudden you were like ‘well… it’s kind of like when you do this.’ So, anytime you’re saying it’s ‘kind of like when,’ that’s usually a warning that maybe something’s not quite working.”